Basically what will happen is that in some month X after IPO the company will be forced to pull back on new driver incentives (the thing that is really making these companies bleed cash), which will slow driver supply growth, which will increase rider wait times and/or make prices spike, which will lower demand, and thus slow growth, and kill the stock price.
I wouldn't touch this at all. Or short it if you're brave :)
If/when Lyft decides it can't grow any more, it will dump the unprofitable cities and focus on the cash cows: LA and New York, etc. The large cities are quite profitable and will be enough.
That said, it's better for society if the unprofitable cities are served by competing ride sharing services. It's kind of like how the US Postal Service makes money in the cities and loses it in rural areas.
I wouldn't touch this at all. Or short it if you're brave :)