It's called making a case. Prosecutors do it all the time. Maybe you can't draw inferences from the transcript, but most people can, based in part on Trump's bullying personality and past history. The difference with an impeachment case is that criminality or civil liability does not have to be proven, and the burden of proof is not as stringent. Nonetheless, with or without Schiff's entertaining and in my opinion accurate and damning assessment, grounds for impeachment are there in abundance. The transcript itself interpreted in the most literal manner is grounds for impeachment. Trump's numerous instances of obstruction of justice uncovered by Bob Mueller are grounds for impeachment. Finally, Trump's statements resulting from his fits of rage in reaction to the impeachment inquiry will result in ever increasing articles of impeachment in real-time.