I don't think it's such an unreasonable question when VCs are trying to maximize their investment, and being in a hot tech market has shown to be an accelerator in finding talent and growing a startup
Additionally, the talent pool skews much younger in hot markets who are on average much more likely to be willing to take a risk and work really hard to make a startup take off.
Obligatory disclaimer that I'm not saying non-hot markets are not filled with great devs and that older people cannot make a startup take off, just the odds are better in one vs. the other.