There's always political risk in any investment, and renewable energy has been on the wrong side of this many times over the last 15 years. However, capping the amount at which one asset class can sell their product feels like a level direct discrimination that would be hard to do without damaging future investment.
The question you pose doesn't really make sense. There are 48 settlement periods in a day, if in any given one of those, 1% of generation came from gas, then the price would be substantially lower than if 20% came from gas. This is because the efficiency varies a lot. Also, it is not only gas that is price setting, all imported power has a price too.
Note that if 0% is from gas the price can go negative, so renewable generators suffer. Or in other words, when there is lots of wind, they receive less revenue - something that is known as cannibalisation, and is only getting worse. There aren't really super returns to be had.
Anyway, to answer your question in another way, do I think renewables are being overpaid? No. Do I think that using gas should be penalised? Yes. Trump is doing his bit for carbon neutrality.