On a case-by-case basis, yes.
Unfortunately, when you are dealing with an entire segment of the population, who all end up with lower salaries, then one is forced to admit that there may be a specific root cause for the imbalance. Regardless of whether that root cause is something along the lines of 'women are less confident in workplace negotiations', the ubiquity of the results still represents a systematic failure to address the gender wage gap.
At best, it indicates that the employers are ignorant of the issue. At worst, they are taking advantage of their female employees, by making lowball offers in the full knowledge that those employees are unlikely to demand the same salary as their male counterparts.
I think the "at worst" is absolutely what happens, but I don't think it is an "at worst" situation as bad as you describe.
Employers know VERY WELL that some people will accept an initially low offer. That is exactly why they make the offer.
Trying to keep it on topic, the fact that women are less likely to negotiate is not discriminatory. Employers will often make a low initial offer to both males and females. It only happens that women are less likely to negotiate. Now if you could demonstrate the lowball offers were substantially lower when made to females then males, you may be on to something. But I don't see that.
One reason the average pay in the games industry is relatively low (compared to similar tech fields) is that so many beginning workers are willing to accept low offers. I have heard from multiple people that when a low offer was made, they essentially replied "Yes, and I'll voluntarily take even less money if you want, just let me make games."
Imagine the conversation. A hiring manager writes: "We would love to hire you. Will you accept the legally required minimum wage?" and the candidate answers "yes". It may seem harsh, but I'm going to claim the employer is not taking advantage of them. The worker accepted the value of the exchange. Note that I didn't mention the job. If a burger flipper accepts a minimum wage offer, or if a skilled professional accepts a minimum wage offer, or if a senior executive accepts a minimum wage offer, it what they negotiated. They accepted that as a fair wage for their time and talents.
Last month a bunch of fast food workers went on strike for a few hours in a 'demand' to earn $15/hr when they were earning around $8/hr. The employer will set the wages to the lowest value the workers will demand. Employers didn't really notice, and there was no change. If the employer can fill the job for $7.50/hr, they will. If they cannot they'll raise it to $8/hr. Then $8.25/hr. Then $8.50/hr. Then $8.75/hr. And eventually someone will take the job at that rate.
Game studios will usually interview a bunch of candidates, and then identify the ones they really want. Then they try to negotiate salary. Those with experience will know the value they provide and they will demand money. I've had companies who said they wanted to hire me ... right up until it came to salary negotiation. I've turned down offers. One came back multiple times asking "what about this offer?", "What about that offer?" "What if we offer a bonus instead?" (Bonuses are garbage, many businesses do a round of firing right before bonuses are calculated.) It is in their interests to pay the minimum possible, it is in my interests to negotiate the maximum. You may feel they are taking advantage of me or I am taking advantage of them, but I disagree. We are both using market forces.
Having seen wages, it is pretty clear who either accepted low values or was hired during employer-powerful times (e.g. glut of workers so they can offer less, worker is getting desperate to accept a job) versus workers hired to fill a specific need (e.g. willing to pay a premium for an experienced network developer, or an experienced recently-released platform developer). You might (as example numbers) see a larger group of programmers with a similar hire date and similar job title all paid in the $65K-$75K range as they were picked up cheaply during a glut, a few people with the same job title hired sporadically for around $85K then see someone with the same job title hired in the middle of a hiring freeze making $110K. It is entirely about supply and demand. If the supply is willing to work for less money, that is what will be paid. If the supply demands a bigger salary, that is what will be paid.
TL;DR: It is not the employer's responsibility to ensure they are paying top value. Employers will tend to pay the minimum amount required to get workers.
But that is only one issue in the "industry misconception" for gender.