System requirements page (http://www.blender.org/download/requirements/) states:
"Graphics card note: Blender runs on all OpenGL-compatible cards, although there are some issues with integrated graphics cards (Intel, Via). We therefore can’t officially support and guarantee that Blender works fine on those systems."
Pre-GL2.0 cards (not necessarily "integrated" ones) are omitted from that note entirely. From those requirements, someone running a GL 1.5 NVIDIA card will expect Blender to work on their system, and while it indeed may run, it's likely to not provide a comfortable working environment.
System requirements should state that Blender might have issues running on GPUs which don't support at least GL2.0.
As new versions are released, more and more people with older GPUs start experiencing issues with viewport. There are a great many of reports on this tracker closed as "driver issue" (simply browse through https://developer.blender.org/maniphest/project/2/type/Bug/query/giiT.ajOPlmN/).
Campbell stated on stackexchange back in 2013 (http://blender.stackexchange.com/questions/451/what-version-of-opengl-does-blender-use), "So while blender depends on version 1.4. it may use newer features when available and fail gracefully if they are not (as opposed to crashing or not starting at all).", but we're nearing on 2016, and that statement is not true anymore. Modern Blender *may* not start on a GL 1.4 GPU, and many of the "graceful" failures are *not* graceful at all (viewport not updating, fonts as squares, pink/white objects in viewport, etc.), with no comprehensive indication that it's indeed a GPU issue, not a misclicked checkbox or a forgotten obscure setting.
Yet there's no "official" word about this on blender.org. Viewing the system requirements page, a user would think "hey, I have an OpenGL card, and it's not integrated, Blender will run fine". But if their card is actually a GL 1.4 or 1.5 one, they would be in for an unpleasant surprise.
Screenshot of 2.76 running on a GL1.5 NVIDIA GPU, from today's question in #blender: