  Recent ALMA observations indicate that the majority of bright protoplanetary
discs show signatures of young moderately massive planets. I show that this
result is paradoxical. The planets should evolve away from their observed
states by radial migration and gas accretion in about 1\% of the system age.
These systems should then hatch tens of giant planets in their lifetime, and
there should exist a very large population of bright planet-less discs; none of
this is observationally supported. An alternative scenario, in which the
population of bright ALMA discs is dominated by secondary discs recently
rejuvenated by deposition of new gas, is proposed. The data are well explained
if the gaseous mass of the discs is comparable to a Jovian planet mass, and
they last a small fraction of a Million years. Self-disruptions of dusty gas
giant protoplanets, previously predicted in the context of the Tidal Downsizing
theory of planet formation, provide a suitable mechanism for such injections of
new fuel, and yield disc and planet properties commensurate with ALMA
observations. If this scenario is correct, then the secondary discs have
gas-to-dust ratios considerably smaller than 100, and long look ALMA and
NIR/optical observations of dimmer targets should uncover dusty, not yet
disrupted, gas clumps with sizes of order an AU. Alternatively, secondary discs
could originate from late external deposition of gas into the system, in which
case we expect widespread signatures of warped outer discs that have not yet
come into alignment with the planets.
