Speaking from the ESA team that co-published those MRO CTX pictures yesterday, your assertions are nonsense and need correcting.
There was a fully coordinated operation in place to track the lander during its descent, using the GMRT in Pune, India, our own Mars Express spacecraft, NASA's MRO, and the ExoMars Trace Gas Orbiter itself, while data came down through our ESTRACK network and NASA's DSN. The Opportunity rover also in Meridiani Planum took images during the descent, but it was known that that would only possibly work if the lander came down at the long end of the landing ellipse: in the event, the targetting was fine, and it came down within ~5km of the centre of the ellipse.
All agencies and partners cooperated fully, as we always do when it comes to Mars (and other solar system) operations, and all data were released as soon as they were available and analysed, including from our own assets. Nobody has been withholding anything beyond the reasonable time needed to analyse the data: we're less than 3 days past the Schiaparelli entry and descent, and a lot of information is already available. The various teams involved are working day and night to understand the complex data.
The MRO CTX images were pre-planned, regardless of a successful landing or not, and were made available by NASA to the ExoMars project team as soon as possible. A number of meetings and joint telecons were held yesterday to analyse and agree on their content to the extent possible (CTX is fairly low resolution: much better information will come via HiRISE when it targets the site next week), and to agree on a time to release them.
Indeed, at ESA, we were working very hard yesterday to publish them jointly as soon as possible, in order to make them available to the European media for last night's news. Due to the timezone different to California, it was challenging for NASA to get the images and accompanying text approved by then, but we're very grateful that they worked hard to make that possible.
Finally, remember that we deliberately sent Schiaparelli there as a test demonstrator. We successfully carried out the hypersonic entry and supersonic parachute deployment phases, prior to the apparent failure during the thruster phase, and telemetry during the whole descent down to the surface were recorded and are back on Earth. Yes, we're obviously very disappointed that we didn't manage the final phase, but we will learn from the data. We also successfully put the main scientific mission, the Trace Gas Orbiter, into orbit around Mars.
We have not withheld information: we've been as open as possible throughout. I'm sure that the truth of the matter won't dissuade you of your "NASA great, ESA bad" opinion, but sometimes it's important to lay out the real story for others to judge.
Bottom line is that Mars was, is, and will always remain hard.