To those of you like me I recommend you to read about what was happening in 95-99. The panorama was crazy, and today's context doesn't compare to the one of those days.
At the end, if the macroeconomic environment changes, who cares? Yes, paying attention to the macro is important and that may even imply changes in strategy, but should you not start a startup because there's a bubble? Even worse, should you (person who hasn't built anything but criticizes everyone who builds something) try to convince your friends not to start startups because we're in a bubble?
The main difference between today and 1999 is that digital products are actually generating value in people's lifes. Please don't compare pets.com to WhatsApp