So, the reason that people want to tax revenue is to negate the benefits of transfer pricing.
For instance, Google France makes 1bn euro in revenue, but purchases Google services from Google Ireland for 999mn, thus almost no profit and thus no tax. Google Ireland make 20bn but pay 19.99bn to Google Bermuda, which is the exclusive licensee of Google IP worldwide (even though the IP is almost exclusively produced in the US).
Taxing revenue means that these shenanigans do not reduce the tax paid in a particular country to zero.
For instance, Google France makes 1bn euro in revenue, but purchases Google services from Google Ireland for 999mn, thus almost no profit and thus no tax. Google Ireland make 20bn but pay 19.99bn to Google Bermuda, which is the exclusive licensee of Google IP worldwide (even though the IP is almost exclusively produced in the US).
Taxing revenue means that these shenanigans do not reduce the tax paid in a particular country to zero.